This section provides background information relating to the present disclosure, which is not necessarily prior art.
A relay user equipment (UE) is introduced in Release 13 (R13) of a Long Term Evolution-Advanced (LTE-A) system. A remote UE far away from a base station may communicate with the base station via the relay UE, and thus a network coverage can be expanded and a cell edge user speed and a frequency spectrum reuse rate can be improved. The relay UE is a foreground technology of the LTE-A system. Practically, in an actual scenario, the relay UE and the remote UE may move continuously, and in this case, the remote UE needs to perform relay reselection continuously to ensure continuity of a service. The relay reselection may be triggered in the following two cases. In a first case, a quality of a PC5 link between the remote UE and the relay UE becomes poor. In a second case, a quality of a Uu link between the relay UE and the base station becomes poor. In the first case, the quality of the Uu link is good and the quality of the PC5 link becomes poor, and the remote UE triggers the relay reselection process based on the signal quality of the PC5. In this case, service interruption only occurs at the remote UE side, and the relay LE is hardly influenced. In the second case, the quality of the PC5 link is good and the quality of the Uu link becomes poor, and whether to perform relay reselection by the remote UE is under a standardized discussion.
In order to ensure the continuity of the service, it is considered that the remote UE needs to perform the relay reselection process when the quality of the Uu link becomes poor in the present disclosure. Practically, in an actual scenario, the quality of the Uu link becomes poor due to multiple reasons, for example, the relay UE is to perform a handover process or the relay UE is to move out of a coverage of a serving cell. For different reasons resulting in that the quality of the Uu link becomes poor, the remote UE and the relay UE may perform different operations. In the conventional technology, the reasons resulting in that the quality of the Uu link becomes poor are not distinguished, that is, the remote UE cannot know a scenario where the relay UE is located and an operation which the relay UE is to perform. Therefore, it is necessary to put forward a new wireless communication technical solution, such that the remote HE can know the scenario where the relay UE is located, so as to assist the remote UE to perform relay reselection or assist the relay UE to perform relay selection.